1. Field of the invention
The present invention relates generally to the art of coverings for doors and windows and more particularly to the preparation of vanes which may be used for such door or window coverings. In its most preferred embodiment, the present invention relates to novel vane structures which include fabric coverings and foam cores. The present invention also relates to a method of making such foam core products.
2. Description of the Prior Art
A wide variety of coverings for doors and windows are known to the art. These include very old products such as roller shades and venetian-type blinds, as well as the newer types of xe2x80x9csoftxe2x80x9d window coverings including pleated and cellular blinds and shades, various light control products, and fabric covered vertical blinds. The latter typically include a track which extends across the opening to be covered, with trucks mounted in the track for movement by a wand device or by cords and pulleys. Vanes are attached to the truck and are pivotable about a longitudinal axis of the vanes to open them to a first position and thus permit light to enter a room and to pivot them to a second position in which the vanes overlie one another, in which case privacy is achieved.
Recently, a number of such vertical blind products have been proposed to include hollow fabric vanes, which can include stiffening compounds to insure that the bottom rotates the same amount as the top with no twist top to bottom to achieve an aesthetically pleasing product. Moreover, light weight fabrics have been attached to thin, rigid vanes to achieve a xe2x80x9cblind with curtainxe2x80x9d product, one of which is disclosed in U.S. Pat. No. 5,638,881 issued to Ruggles, et al. on Jun. 17, 1997 and entitled xe2x80x9cBLIND WITH CURTAINxe2x80x9d.
It has also been proposed that vanes for door and window coverings can be prepared in a tubular configuration, the cross-section of such vanes simulating an air foil. They are preferably made from material having diagonal, dimensional stability or memory so that they resist stretching in the longitudinal direction. It is also known that with such vanes, a reinforcing strip can be applied to an open end of the vane to provide a positive and durable attachment for supporting the vane from an operating system. One patent describing such vanes is U.S. Pat. No. 5,797,442, issued Aug. 25, 1998 to Colson, et al., for xe2x80x9cVanes For Architectural Covering and Method of Making Samexe2x80x9d.
The vanes used in the aforementioned Colson, et al. patent have a cross sectional configuration best illustrated in FIG. 6d of the patent, i.e., one resembling an air foil. Various techniques are described for insuring that the shape is maintained, such as the use of stiffening compounds, or in the embodiment shown in FIG. 12, the use of a resilient rubber strip along the inside of the vane, i.e. at the blunt end. Various single and double thickness vanes and further vane structures are also disclosed in PCT International Application WO96/35881, to the same inventor, which application claims priority to the parent application of the aforementioned ""442 Colson, et al. patent.
FIG. 1 of the Colson, et al. patent discloses a vertical arrangement in which a plurality of the vanes are suspended from a track 30 and are pulled across the opening to be covered using a wand. The vanes may also be rotated to an open, light-admitting position as shown in FIG. 1, or to a privacy position, shown in FIG. 3. If the vane is constructed from transparent or sheer materials, light can be admitted in a diffused pattern into the room when in the closed position, as illustrated in FIG. 4 of this patent.
While new window coverings are shown in the PCT application and the issued Colson, et al. patent, a variety of different and useful door and window coverings employing foil shaped vanes are not disclosed or contemplated. Furthermore, while some thermal insulation benefits may be obtained by using hollow vanes, the amount of insulation is relatively modest. Moreover, the hollow vanes employing fabric are delicate and will quickly become damaged in more severe end use applications. A door or window covering which overcomes these and other disadvantages of the prior art door and window coverings would be a significant advance in this art.
A primary feature of the present invention is to provide a new foam core vane for door and window coverings.
Another feature of the present invention is to provide a method of manufacturing a new foam core vane for door and window coverings.
A different feature of the present invention is to provide an improved vane for door and window coverings which may be hung horizontally or vertically.
Another feature of the present invention is to provide a vane for door and window coverings which has high insulation characteristics when the vanes are in a position in which they overlap one another.
Yet another feature of the present invention is to provide a vane for door or window coverings which may be constructed from a wide variety of exterior covering materials.
How the foregoing and other features of the present invention are accomplished will be described in the following detailed description of the preferred embodiment, taken in conjunction with the FIGURES. Generally, however, the features are provided in a vane which, in cross-section, is generally in the shape of an air foil and which includes a fabric exterior and a foam core, preferably a core made of urethane or polyisocyanurate foam. The vanes are manufactured by folding a strip of material to form a receiving area for the deposit of foam-forming chemicals, continuing to fold the material and passing the material into a mold including upper and lower mold cavities which together define the desired final shape for the vane. Preferably, the mold is a traveling mold and the foam expands within the mold to fill the mold and press the fabric covering against the interior mold surface. An adhesive may optionally be applied to connect the two edges of the strip at what becomes the thin or rear of the foil. When the vane leaves the mold area, it is cut into desired lengths by a cutting means, such as a rotary knife. Other ways in which the above and other features of the invention are accomplished will become apparent to those skilled in the art after they have read the remainder of this specification, such other ways falling within the scope of the present invention if they fall within the scope of the claims that follow.